Summary

The National Longitudinal Study of Adolescent Health (Add Health) is a longitudinal study of a nationally representative sample of adolescents in grades 7-12 in the United States during the 1994-1995 school year. The
Add Health cohort has been followed into young adulthood with four in-home interviews, the most recent in 2008, when the sample was aged 24-32. Add Health combines longitudinal survey data on respondents' social, economic, psychological, and physical well-being with contextual data on the family, neighborhood, community, school, friendships, peer groups, and romantic relationships, providing unique opportunities to study how social environments and behaviors in adolescence are linked to health and achievement outcomes in young adulthood. The fourth wave of interviews expanded the collection of biological data in Add Health to understand the social, behavioral, and biological linkages in health trajectories as the Add Health cohort ages through adulthood. The files contained in this component of the Add Health restricted data are Waves I-III Contextual Files Data, Waves I-II Neighborhood Data, Wave I Spatial Analysis Data, Waves III-IV Grouping File Data, and Waves III-IV Census Region data. The contextual files data contain community contextual variables based on state, county, tract, and block group levels derived from Waves I, II, and III addresses. The neighborhood data and grouping file data contain pseudo state, county, tract, and block group variables that allow grouping Add Health respondents geographically. Wave I Spatial Analysis Data include X, Y coordinates that can be used to calculate distances between friends in a school community. For more information, please see the study website.

Funding

United States Department of Health and Human Services. National Institutes of Health. Eunice Kennedy Shriver National Institute of Child Health and Human Development (P01-HD31921)

United States Department of Health and Human Services. National Institutes of Health. National Cancer Institute

United States Department of Health and Human Services. Centers for Disease Control and Prevention. Office of Minority Health and Health Disparities

United States Department of Health and Human Services. National Institutes of Health. National Institute of Nursing Research

United States Department of Health and Human Services. National Institutes of Health. Office of AIDS Research

United States Department of Health and Human Services. Centers for Disease Control and Prevention. National Center for Health Statistics

United States Department of Health and Human Services. National Institutes of Health. Office of Behavioral and Social Sciences Research

United States Department of Health and Human Services. Office of the Assistant Secretary for Planning and Evaluation

United States Department of Health and Human Services. Office of Public Health and Science. Office of Population Affairs

United States Department of Health and Human Services. National Institutes of Health. Office of Research on Women's Health

United States Department of Health and Human Services. National Institutes of Health. National Institute on Alcohol Abuse and Alcoholism

United States Department of Health and Human Services. National Institutes of Health. National Institute on Deafness and Other Communication Disorders

United States Department of Health and Human Services. Office of Public Health and Science. Office of Minority Health

United States Department of Health and Human Services. National Institutes of Health. National Institute on Drug Abuse

United States Department of Health and Human Services. National Institutes of Health. National Institute of General Medical Sciences

United States Department of Health and Human Services. National Institutes of Health. National Institute of Mental Health

Sample

Wave I, Stage 1 School sample: stratified, random sample of all high schools in the United States. A school was eligible for the sample if it included an 11th grade and had a minimum enrollment of 30 students. A feeder school, a school that sent graduates to the high school and that included a 7th grade, was also recruited from the community. Wave I, Stage 2: An in-home sample of 27,000 adolescents was drawn consisting of a core sample from each community plus selected special over samples. Eligibility for over samples was determined by an adolescent's responses on the In-School Questionnaire. Adolescents could qualify for more than one sample. In addition, parents were asked to complete a questionnaire about family and relationships. The Wave II in-home interview sample is the same as the Wave I in-home interview sample, with a few exceptions. Information about neighborhoods/communities was gathered from a variety of previously published databases. Wave III: The in-home Wave III sample consists of Wave I respondents who could be located and re-interviewed six years later. Wave III also collected High School Transcript Release Forms as well as samples of urine and saliva.

(1) Part 7 (Wave III Grouping File Data) was updated to correct an error in the data that erroneously displayed a higher number of valid observations than were actually recorded. The data have not been changed otherwise.

(2) The label of variable "W4GROUP0" in Part 10 (Wave IV Grouping File Data) has been changed to "WAVE IV GROUPING VARIABLE CENSUS 2000 FIPS CODE". Also, the word "PSEUDO" was added to the labels of both census grouping variables, as they are not actual FIPS codes but are FIPS-like codes.

(3) In Part 12 (Wave IV Supplemental Tract-Level Contextual Data), the codebook has been updated to include the mover variable description. The changes are textual only, and none of the data has been changed.

2012-11-01 Parts 8 and 9 were added, and they include Wave III and Wave IV Census Region data, respectively. Documentation files, including ICPSR codebooks and the original codebooks supplied by the principal investigators, were also added for Parts 8 and 9.

2013-08-15 (1) Part 10 (Wave IV Grouping File Data) was updated to correct an error in the data that erroneously displayed a higher number of valid observations than were actually recorded. The data have not been changed otherwise.

2010-01-14 ICPSR data undergo a confidentiality review and are altered when necessary to limit the risk of disclosure. ICPSR also routinely creates ready-to-go data files along with setups in the major statistical software formats as well as standard codebooks to accompany the data. In addition to these procedures, ICPSR performed the following processing steps for this data collection:

Performed consistency checks.

Standardized missing values.

Checked for undocumented or out-of-range codes.

2013-04-23 Part 10 (Wave IV Grouping File Data), Part 11 (Wave III Supplemental Tract-Level Contextual Data), and Part 12 (Wave IV Supplemental Tract-Level Contextual Data) were added to the data collection. Additionally, both the original codebook supplied by the principal investigators as well as the ICPSR codebook for all three parts were added.